I. Field
The present disclosure relates generally to wireless communications, and more specifically to techniques for managing resource assignments in a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various communication services; for instance, voice, video, packet data, broadcast, and messaging services may be provided via such wireless communication systems. These systems may be multiple-access systems that are capable of supporting communication for multiple terminals by sharing available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems.
Multiple-access communication systems typically employ methods of assigning system resources to individual users in the system. Resource assignments can be given a predetermined duration in time or made persistent or “sticky” such that they do not have a set time for expiration. Persistent resource assignments can be used, for example, in voice applications or other wireless communication applications where periods of data packet transmission to a receiver are interspersed with periods where no data packets are transmitted to the receiver. However, in such applications, a receiver using a persistent assignment of resources may not be readily able to determine when a data packet is being transmitted. This inability to determine periods of data packet transmission can lead to reduced inefficiency of the receiver in decoding packets.
To mitigate the difficulties experienced by receivers utilizing persistent assignments of resources, an access point that transmits data packets to such receivers can manage the assignments by communicating keep-alive messages to the receivers. Keep-alive messages communicated by an access point can indicate whether a data packet is being transmitted, and from this information a receiver can receive and decode a data packet if one has been transmitted or wait and hold the persistent assignment if one has not been transmitted. However, when the number of receivers in the system having persistent resource assignments is large, the required system overhead for transmitting keep-alive messages to each receiver can become significant. Consequently, the required overhead for managing persistent resource assignments in a wireless communication system can adversely impact the performance of the system.